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Purpose Permanent magnet (PM) electrical machines are becoming one of the most popular type of the machines used in electrical vehicle drive applications. The main drawback of permanent magnet machines, despite obvious advantages, is associated with the flux control capability, which is limited at high rotor speeds of the machine. This paper aims to present a new arrangement of permanent magnets and flux barriers in the rotor structure to improve the field weakening control of hybrid excited machines. The field weakening characteristics, back-emf waveforms and efficiency maps of this novel machine have been reported. Design/methodology/approach In the study, finite element analysis was used to perform simulation research. Then, based on the simulation studies, an experimental model was built. The paper also presents selected experimental results. Findings Obtained results show that the proposed machine topology and novel control strategy can offer an effective flux control method allowing to extend the maximal rotational speed of the machine at constant power range. Practical implications The proposed solution can be used in electric vehicles drive to extend its torque and speed range. Originality/value The paper presents original design and results of research on a new solution of a hybrid excited machine with magnetic barriers in a rotor.

Propulsion shaft torque measurement is essential in ship energy efficiency evaluation and emission control. Its accuracy and uncertainty influence decision making in terms of voyage optimisation and fuel consumption. For best results, the measuring device should be adjusted and calibrated adequately. This paper analyses the problem of ship propulsion shaft torque meter zero adjustment. Presented results of initial investigation suggest significant unrepeatability of the torque observed when the propulsion unit is at a standstill. Using a recently designed telemetry torque meter and an older analogue device a series of experimental research was conducted on board of a ship and on marine propulsion units installed in a laboratory. A new statistical method for zero adjustment is proposed and evaluated against methods commonly used on ships. The survey results suggest that the new method is burdened with a lower random error compared to presently used methods and uniquely allows for uncertainty evaluation.

The paper contains results of simulation research of a hybrid excited machine - Electrically Controlled Permanent Magnet Excited Synchronous Machine (ECPMSM) - with three construction concepts of the rotor. Selected experimental results of the prototype with two rotor's construction variants are also presented. In addition, in order to compare the properties at high rotational speeds for presented rotor designs, the expected performance, i.e. the range of speed and torque of the machine and the possibility of the excitation field weakening, were evaluated.

Paper discusses the design idea, construction of the prototype measurement unit and experimental verification of an automated test stand for transformer inrush current identification. Transformers of different size and construction are key components in power systems and power supply units. Proposed test stand construction allows automated inrush current measurement and maximum inrush current identification for tested transformers. Presented experimental results are provided for toroidal core transformers.

The paper presents selected results of the 3D finite element analysis (3D-FEA) and experimental validations of a hybrid excited synchronous machine which contains magnetic barriers and permanent magnets inside the rotor. In the paper machine torque, no-load magnetic flux linkage, back-EMF, efficiency maps and field control (FC) characteristics have been presented and described. Moreover FC characteristics depending on machine DC control coil excitation have been estimated. Results of the 3D-FEA were compared with real measurements for validation purposes.

Proposed paper gives an overview of the design and performance of a power electronic converter designed to efficiently rectify the alternating voltage of the permanent magnet AC generator to direct current, that may be used to charge batteries and/or power devices from a small hydrogenerator. The generator design is also briefly discussed aimed for electricity generation by the motion of an undersail boat. Simulation results and test — stand results are presented.

Proposed paper discusses a construction and characteristics of a switched mode power controller operating as adjustable load controller. Unique converter topology allows high efficiency operation for a wide range of input voltage change. This feature together with a simple construction make it an interesting choice for applications starting with renewable energy sources up to controllable loads for the testing of performance of electric machines. Natural oscillating character of the input is damped using the averaged current measurement concept. Simulation and experimental results are shown and discussed.

This paper deals with the optimal design of a new synchronous motor particularly suitable for electric vehicles. The unique advantage of this motor is its possibility to realize field weakening at high speeds, which is the most important demand for such drives. The main design goal is to identify the dimensions of certain crucial regions of the machine in order to avoid saturation of the iron and to minimize the mass to volume ratio, while simultaneously maximizing the torque. The originality of the contribution is manifold: formulating the design problem in multiobjective terms, solving it by means of evolutionary computing, solving the associated direct problem based on a three-dimensional finite element analysis (3-D-FEA) field model, considering a reduced set of design variables by means of response surface method, referring to a real-life problem.

Direct and indirect plasma oxidation of NO x was tested in a medium-scale test-bench at gas flows of 50 slm (3 m 3 /h). For direct plasma oxidation the synthetic flue gas was directed through a stacked DBD reactor. For indirect plasma oxidation, a DBD reactor was used to generate ozone from pure O 2 and the plasma treated gas including ozone was mixed with flue gas at the entrance of a 6 m long serpentine-like reaction chamber which allowed reaction times longer than 10 s. At relatively low NO x concentrations of 200 ppm, both oxidation methods gave similar results. However, the temperature increase of the DBD reactor decreased the long-term efficiency of direct plasma oxidation. At the same time, the efficiency of indirect oxidation increased at elevated reactor temperatures. Additional experiments were carried out to investigate the improvement of indirect oxidation by the introduction of catalyst to the reaction zone. Small-scale experiments with TiO 2 powder demonstrated considerable efficiency gain for NO x oxidation while in medium-scale experiments, the efficiency improvement remained negligible.

The paper presents selected simulation and experimental results of a hybrid ECPMS-machine (Electric Controlled Permanent Magnet Synchronous Machine). This permanent magnets (PMs) excited machine offers an extended magnetic field control capability which makes it suitable for battery electric vehicle (BEV) drives. Rotor, stator and the additional direct current control coil of the machine are analyzed in detail. The control system and strategy, the diagram of power supply system and an equivalent circuit model of the ECPMS-machine are presented. Influence of the additional excitation on the performance parameters of the machine, such as: torque, efficiency, speed limits and back-EMF have also been discussed.

Paper describes the system design of modern power electronics laboratory test stands intended for electrical engineering schools and universities. Proposed system design simplifies the configuration of the lab and maximizes the time that the students can use for experimental measurements and converter characterization. System pre-configuration is constant for all exercises so the students do not need to learn the system design of every particular test stand. It also provides clear measurement readings and protection loops so number of errors or damages of the hardware during testing is minimized.

The paper presents the results of research work on the development of a rapidprototyping test stand for testing: servo control algorithms, trajectory generation, algorithms for increasing overall quality of the feed-drive modules within two axis (X-Y) table of the milling machine. Open architecture interface of the prepared control system lets the potential user test functionality of integration of diagnostic tools within the motion controller - directly, without taking into account communication with top-level CNC system.

The paper presents the optimization and comparison of different rotor design concepts of an Electrically Controlled Permanent Magnet Excited Synchronous Machine (ECPMSM) possessing a field control capability. The experimental results of a no-load back electromotive force (back-EMF) waveforms, cogging torque and electromagnetic torque values are presented in detail. Moreover, in order to compare the over-speed capability of the machine in the varying rotor designs, the predicted performances, i.e. range of speed and resulting torque of the machines, have been estimated.

Proposed paper presents a fast algorithm for determining static and switching losses of power electronic devices in three-phase DC/AC inverters for different semiconductor materials. This method uses table — form, stored characteristics of individual semiconductor devices, without a necessity of detailed, time resolved analysis of the commutation process. Using such algorithm accelerates total loss calculation, as a result electric machine control strategy can be developed allowing the improvement of the efficiency of the entire propulsion system.

The paper introduces an “a-priori” look-up-table procedure for an efficiency-optimal inverter-machine control system. This method has been applied for a hybrid excited permanent magnet synchronous machine. An exemplary machine model is proposed and a prototype is introduced with stator-located excitation coil. An iterative process for optimal current distribution is described, including multidimensional tables of overall losses and efficiencies. Based on appropriate calculations, an optimization algorithm can be implemented for various target functions, including classic permanent magnet synchronous machines. The proposed approach has been validated using experimental data. Experimental test-bench construction is presented, along with basic discussions on the methodology. Modeling and measurement results are presented, along with corresponding conclusions. A decrease of up to 6% of overall system losses was measured, mostly in the high speed range of the machine.

This paper discussed a control system for an HPMSM machine with a stator based field coil aiming at maximum efficiency of the inverter-machine system. A new procedure for efficiency-optimal inverter-machine propulsion system has been introduced. An iterative process for optimal current distribution is described with multidimensional tables of overall losses and efficiencies. Due to high-speed calculations, optimization algorithm can be implemented for various goal functions including classic PMSM drivetrains.

Effects of space vector modulation strategy on hybrid (Si-SiC) inverter lossesThis work summarizes efficiency measurement results of a full bridge, 3 phase inverter composed of state-of-the-art Si IGBT transistors and Si or SiC diodes. Different (symmetrical and discontinuous) space vector modulation strategies were chosen in order to examine their influence (together with modulation frequency) on inverter losses. Induction machine was used as load, different load points were examined. Results clearly show, that proper modulation strategy, minimizing the switching losses of semiconductor switches, can increase the overall output efficiency at about 1% in case of both silicon and hybrid constructions. The drawback of DPWM approach is connected with the decreased quality of inverter output current. Hybrid technology can also improve the output efficiency at about 1% when compared to traditional constructions, but only in case of elevated switching frequencies. At low frequencies (below 10 kHz) modern semi-conductors offer comparable results at much lower device costs.

The paper presents an unconventional approach to control Electric Controlled Permanent Magnet Synchronous Machine (ECPMSM) with universal method to determine its required parameters. Moreover, two different kinds of supply the additional control coil of the prototype machine have been analyzed in details. In the first variant, the control coil is placed within the stator part of the machine, thus the whole power supply system can be simplified. In the second variant, the additional control coil is placed on the rotor of the machine. This design solution allows to reduce control coil's losses but it causes additional complications in the way of energy distribution.